Brake for pulleys



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INVENTR /o UNITED STATES PATENT Genion.

BENJAMIN F. RADFORD, OF HYDE PARK, MASSACHUSETTS.

BRAKE FOR PU LLEYS.

SPECIFICATION forming part 0f Letters latent No. 500,611, dated July 4,1893.

Application filed September 15, 1892.- Serial No. 446,017. (No model.)

To all whom it may concern:

Be it known that I, BENJAMIN F. RADFORD, a citizen of the United Statesof America, and a resident of the town of Hyde Park, in the county ofNorfolk and State of Massachusetts, have invented a certain new anduseful Improved Brake for Pulleys, of which the following is a full,clear, and. exact description.

The brake for pulleys of this invention, in substance, consists ofbrake-shoes located to work against the inner and opposite sides of thesurface of the rim of the pulley, separate carriers, one for each ofsaid shoes, and both at one end swinging about a common central orotherwise suitable pintle and at the other end joined. by twotoggle-arms having one end of each at abearing on an inner face of eachof said carriers, and the other end of both at a bearing on but atopposite ends of a oommon-block which is held on an arm supported fromsaid pintle and is arranged for a movement lengthwise through said arm,and in an axial direction parallel with the axis of the pulley, allsubstantiallyT as hereinafter described.

In the drawings, forming part of this speciication, Figure l is a sideelevation of a pulley andacentral vertical section of the brakemechanismfor and on a plane parallel with the opposite sides of the pulley. Fig.2 is a horizontal section, line 2 2, Fig. l. Fig. 3 is an enlargedvertical section, in detail, line 3 3, Fig. l.

In the drawings,Ais a hollow or chambered pulley having a hub B at andprojecting from one of its sides.

C, C2 are two brake-shoes made of any suitable material and each shapedto embrace a portion of the inner surface of the rim of the pulley, thetwo portions, preferably, being of corresponding width and length. Eachybrakeshoe C, C2 is suitably held on and projected from a similar carrierD, D2. At one side of the pulley both carriers are hinged and swing on acommon pintle E as a center and they are held against movementlengthwise of the pintle by and between a iixed shoulder E2 at oneend-portion and a screw-nut F.3 at the other end-portion of the pintle,and at the other side of the pulley these carriers are joined togetherby a toggle-lever mechanism, to be now described.

F, F2 and F3 are the two arms of the togglelever. The toggle-arm F, F2is in two parts and the part F is adapted to be screwed lengthwise intoand out of a threaded lengthwise socket of the part F2, all so that thearm at pleasure may be lengthened or shortened.

The outer ends of each part of the two part toggle-arm F, F2 and alsothe opposite ends ot the toggle-arm FB are severally rounded off or ofhemispherical shape, and both arms are placed lengthwise and in linewith each other between the ends D3, D4 respectively of the twobrake-shoe carriers D, D2, and the outer rounded end of each toggle-armis seated in a correspondingly rounded or hemispherical bearing-socketof said ends D3,D4 of said carriers. The ends of the toggle-arms towardeach other seat in corresponding rounded or hemisphericalbearing-sockets at the opposite ends of a cylindrical block G, in linewith said arms, and this block is at the projecting endportion of acylindrical rod or shaft H axially at right angles to the axial line ofthe block G and arranged to have a forward and backward movement througha suitable bearing at the outer end of an arm J, forming part of thestationary frame, which arm, at its opposite end, has ixed on it thepintle E about which the brake-shoe carriers swing as stated.

As is obvious, by sliding the rod H in either direction through itsbearing ofthe arm J, the toggle-arms are simultaneously moved and if itis in one direction,by aswing of the brakeshoe carriers, the brake-shoesare forced apart and into contact with the inner surface of the rim ofthe pulley and if it is in the other direction the pressure on thebrake-shoe is thus relieved and in consequence the brake-shoes movetoward each other and away from the inner surface of the rim of thepulley, all as is obvious without further explanation.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

The combination with a pulley, of a brake and toggle lever mechanism,consisting of brake-shoes located to work on the wheel at opposite sidesot the inner surface of its rim,

IOO

a carrier for each brake-shoe and both at onev at one end the pintle Eof the brake-shoe carend adapted to swing on a common pintle E,

riers and at the other end receiving and suptwo toggle-arms extendingbetween the outer porting the rod H, substantially as described,

ends of said brake-shoe carriers and both, at one end, having a bearingon said ends of said carriers, a block G located between the ends of thetoggle levers which are toward each other, and said ends having bearingson 0pposite ends of said block, a rod H carrying said block G andextending therefrom in a direction axially parallel to the axis of thepulley and a stationary armJ having fixed on it,

for the purposes specified.

In testimony whereof I have hereunto set my hand in the presence ot tWosubscribing Witnesses.

BENJ. F. RADFORD.

Witnesses:

E. E. CHANDLEE, G. H. COX.

